Research in the Department of “Applied Ecology and Phycology” of the University of Rostock
We are investigating the adaptive mechanisms of microalgae and macroalgae living in extreme habitats, from the polar regions to the Atacama Desert. Algae are of great ecological importance because they are very productive and serve as a food source for other living organisms. It is important to determine how these organisms respond to climate change because the consequences for these key species and their functions in the ecosystem are still unknown. Another aspect of our research is to be able to harness functions that nature provides for human applications.
Extreme habitats are usually characterized by the following conditions:
Extreme temperatures
Terrestrial algae in soil crusts are exposed to strong temperature differences, due to fluctuations in the course of the day and year.
Increased UV exposure
Hard ultraviolet radiation (UV-B, wavelength: 280-315 nm) is increasing in many regions of the world due to stratospheric ozone depletion. UV-B has a gene-modifying effect and damages numerous biomolecules and processes in the cell. However, many algae protect themselves with specific sunscreen substances. The use of these substances for cosmetic and pharmaceutical applications is currently investigated in cooperation with the University of Innsbruck.
Desiccation
Terrestrial algae in soil crusts are often exposed to desiccation stress. Water is only available after rainfalls, at least for a short time, but it is absent during dry periods. Many terrestrial microalgae synthesize and accumulate sugar alcohols as protective substances to better retain water in the cells and, thus, counteract desiccation stress.
Under controlled laboratory conditions, we investigate the ecophysiological, biochemical, and molecular-biological basis of adaptation to these and other environmental factors and compare the obtained data with the field.
Research questions
- Which algal species occur at extreme sites (biodiversity)?
- What are the cell-biological, physiological, biochemical, and molecular adaptation mechanisms that enable algae to survive at extreme sites?
- How, by which mechanisms, and with which consequences are biotic interactions in polar regions altered by climate change (e.g., parasitism)?
Methods
- Fieldwork, collection of environmental parameters, sampling techniques.
- Algae isolation, purification, and establishment of clonal cultures
- Simulation of environmental stress experiments under controlled conditions
- Measurement of photosynthetic and respiratory activity with oxygen optodes
- Measurement of growth limits and optima with fluorescence-based methods
- Application of mathematical models for physiological processes
- Analysis of stress metabolites, chemical structure elucidation
- Molecular biological methods (metagenomics, transcriptomics)
- Microscopic techniques (light-, epifluorescence-, confocal laser- and electron microscopy, staining techniques)
Responsible persons
Prof. Ulf Karsten, Applied ecology and phycology, University of Rostock and team
Cooperation partners
Prof. Hans-Peter Grossart und Doris Ilicic (Parasites of benthic diatoms)
Dr. Jonas Zimmermann und Katherina Schimani (Biodiversity of benthic diatoms)
Prof. Burkhard Becker und Dr. Ekaterina Pushkareva (Polar soilcrusts)
Prof. Andreas Holzinger (Cell biology of benthic diatoms)
Prof. Markus Ganzera, Prof. Johanna Gostner, Prof. Thomas Werner (UV-protection substances in fish eyes)
Dr. Karin Glaser und Dr. Kenneth Dumack (Algivorous Cercozoa)
Projects we participate in
The ecological role of fungal parasites on benthic diatoms of polar coastal waters.
Ecological role of fungal parasites on benthic diatoms of polar coastal waters – Angewandte Ökologie & Phykologie – Universität Rostock (uni-rostock.de)
Biodiversity and biogeography of marine benthic diatoms in Antarctic and Arctic coastal waters to verify the presence of endemism using high-resolution taxonomy and eDNA metabarcoding
Biodiversity and biogeography of marine benthic diatoms from polar regions – Angewandte Ökologie & Phykologie – Universität Rostock (uni-rostock.de)
Algivorous Cercozoa shape the community composition of cryptogamic covers, the dominant vegetation in Polar Regions. DFG SPP 1158
Dumack_2020 – DFG-Schwerpunktprogramm 1158 – Antarktisforschung – Universität Rostock (uni-rostock.de)